The present invention generally relates to a method for controlling a terminal equipment coupled to an integrated services digital network and a terminal equipment based on the same.
Recently, there has been considerable activity in the development of an integrated services digital network (hereinafter simply referred to as an ISDN). Currently, data terminal equipments for exchanging data with an ISDN have been put to practical use. An ISDN will take place of a public services telephone network (hereinafter simply referred to as a PSTN) in the feature. However, both ISDN and PSTN will be used until the ISDN is completely substituted for the PSTN. In order to construct a network including both the ISDN and PSTN, internetworking has been proposed, which enables it to be possible to exchange data between the ISDN and PSTN.
In the above-mentioned circumstance, a group 4 facsimile machine which uses an ISDN as a transmission line is required to exchange data with a group 3 facsimile machine which uses a PSTN as a transmission line. In order to meet this requirement, it is necessary to determine, prior to starting a transmission control procedure for image information transmission, as to whether a destination terminal is a group 4 facsimile machine coupled to an ISDN or a group 3 facsimile machine coupled to a PSTN.